title: Flow-mediated vasodilatation: variation and interrelationships with plasma lipids and lipoproteins.
abstract: OBJECTIVE
  Endothelial dysfunction is a critical, prerequisite step in atherosclerosis, and may be evaluated by flow-mediated vasodilatation (FMD). The objective of this study was to examine interrelationships between FMD and plasma lipids and lipoproteins, and to determine the between-operator and within-subject variability associated with this technique.
  
  
  METHODS
  FMD, plasma lipids and lipoproteins, including small dense LDL (sdLDL), were measured twice in 40 healthy volunteers, 4 weeks apart. Interrelationships between mean FMD responses and plasma lipids and lipoproteins were examined by correlation analysis. FMD measurements were taken by two independent operators, allowing determination of between-operator variability. Within-subject variability was determined by obtaining two measurements, 4 weeks apart, in every subject, and carried out by the same operator.
  
  
  RESULTS
  FMD was inversely related to plasma triglycerides (r = -0.47, p = 0.002), total cholesterol/HDL cholesterol (r = -0.35, p = 0.03) and apolipoprotein B (r = -0.36, p = 0.02), but not to other plasma lipids and lipoproteins. When measuring variation in FMD, the following results were found: Between operators (SD = 4.0 FMD%) and within subjects (SD = 2.9 FMD%).
  
  
  CONCLUSIONS
  The associations between FMD, plasma triglycerides and apoB provide evidence supporting a role for triglyceride-rich lipoproteins in endothelial dysfunction.
authors.affiliation: Department of Cardiology, Center for Cardiovascular Research Aalborg Hospital, Arhus University Hospitals, Denmark. jgr1@dadlnet.dk
authors.forename: Jeppe Grøndahl
authors.initials: JG
authors.lastname: Rasmussen
authors.forename: Rikke Bülow
authors.initials: RB
authors.lastname: Eschen
authors.forename: Inge Valbak
authors.initials: IV
authors.lastname: Aardestrup
authors.forename: Claus
authors.initials: C
authors.lastname: Dethlefsen
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Griffin
authors.forename: Erik Berg
authors.initials: EB
authors.lastname: Schmidt
mesh_terms: D000328:Adult; D000368:Aged; D001158:Arteries / Q000502:physiology; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow / Q000502:physiology*; D014280:Triglycerides / Q000097:blood; D014664:Vasodilation / Q000502:physiology*
chemical_list: D008074:Lipoproteins; D014280:Triglycerides